Es mejor que escanees el formulario antes de enviarlo, a no ser que la oficina ya lo tenga.

Because es mejor que is an expression of advice or recommendation, and in Spanish that normally triggers the subjunctive.

So:

• Es mejor que escanees... = It’s better that you scan...
• Escaneas is indicative, so it would sound wrong here.

Very common pattern:

• Es bueno que...
• Es importante que...
• Es mejor que...

All of these are usually followed by the subjunctive.

Escanees is the present subjunctive form of escanear for tú.

Steps:

1. Start from the yo form in the present indicative: escaneo
2. Remove the -o: escane-
3. Add the subjunctive ending for tú: -es

So:

• yo escanee
• tú escanees
• él/ella/usted escanee
• nosotros escaneemos
• vosotros escaneéis
• ellos/ellas/ustedes escaneen

It may look a bit unusual because the verb ends in -ear, but this is the normal pattern.

Because the subject is the same in both actions: you scan it and you send it.

When the subject stays the same, Spanish normally uses:

• antes de + infinitive

So:

• antes de enviarlo = before sending it / before you send it

If the subject changes, then Spanish usually uses:

• antes de que + subjunctive

For example:

• Escanéalo antes de que la oficina lo reciba.
  • Scan it before the office receives it.

So in your sentence, antes de enviarlo is the natural choice.

Enviarlo = to send it

It is made of:

• enviar = to send
• lo = it

In Spanish, object pronouns can attach to an infinitive:

• enviarlo
• hacerlo
• leerlo

You could also sometimes place the pronoun before a conjugated verb in other structures, but with a bare infinitive like this, attaching it is the normal form.

Here lo refers to el formulario.

A no ser que means unless.

So this part:

• a no ser que la oficina ya lo tenga

means:

• unless the office already has it

It introduces an exception to the advice in the first part of the sentence:

• It’s better to scan the form before sending it,
• unless the office already has it.

A close synonym is a menos que.

Because a no ser que is one of the expressions that normally requires the subjunctive.

So:

• a no ser que la oficina ya lo tenga
• unless the office already has it

Here, tenga is the present subjunctive of tener.

This happens because unless introduces something conditional, uncertain, or presented as an exception rather than as a straightforward fact.

Lo refers back to el formulario.

So:

• la oficina ya lo tenga = the office already has it

Even though formulario is masculine singular and has already been mentioned, Spanish often repeats it with a pronoun rather than repeating the noun itself.

So instead of saying:

• ...que la oficina ya tenga el formulario

the sentence says:

• ...que la oficina ya lo tenga

Both are possible, but the pronoun is very natural and avoids repetition.

Because both times it refers to el formulario, but in two different parts of the sentence:

1. antes de enviarlo

   • lo = it
   • before sending it

2. la oficina ya lo tenga

   • lo = it
   • the office already has it

Spanish often uses object pronouns whenever the object is understood from context, even if the noun has already appeared earlier in the sentence.

Ya means already.

So:

• la oficina ya lo tenga = the office already has it

It suggests that maybe sending or scanning the form is unnecessary if the office has it on file or in its possession already.

Without ya, the meaning would be a bit less specific:

• ...que la oficina lo tenga = ...that the office has it

With ya, the sentence emphasizes that this may have happened before now.

Yes, but it changes the structure and slightly changes the feel.

• Es mejor que escanees el formulario...

  • direct advice to you
  • It’s better that you scan the form...

• Es mejor escanear el formulario...

  • more general, more impersonal
  • It’s better to scan the form...

So both are possible, but the original sentence is more directly addressed to the listener.

Not necessarily. In Spanish, la oficina can mean:

• the office as a place,
• the office staff,
• the department,
• the administrative office handling the form.

In this sentence, it most likely means the office/department responsible for the paperwork, not just the physical room.

So la oficina ya lo tenga is better understood as:

• the office already has it on file or
• the department already has it

Not exactly.

• formulario = form
• solicitud = application/request
• impreso can also mean a printed form in some contexts

Formulario is a very common general word for a form you fill in. In administrative contexts in Spain, it sounds completely natural.

Depending on context, another word might be used, but formulario is a safe and standard choice.

Yes, it works perfectly in Spain Spanish, but it is also widely understandable across the Spanish-speaking world.

A few notes:

• escanear is standard and commonly used in Spain.
• The sentence uses tú forms: escanees
• In Spain, that is natural when speaking informally to one person.

If you were addressing someone formally, you would say:

• Es mejor que escanee el formulario antes de enviarlo, a no ser que la oficina ya lo tenga.

If you were speaking to more than one person in Spain:

• Es mejor que escaneéis el formulario...

So the grammar fits Spain Spanish well.